Working pipe operator today in pure JavaScript

Post by mlajtos » Wed, Oct 08, 2025, 9:24 PM UTC

    Object.prototype.pipe = function(fn) { return fn(this) }

    'hello'.pipe(upper).pipe(ex('!!!'))

    Object.prototype.P=function(...F){return F.reduce((v,f)=>f(v),this)}
    'hello'.P(upper,ex('!!!'))

Post by hinkley » Wed, Oct 08, 2025, 9:49 PM UTC

nticompass wrote: post #77

Ciantic wrote: post #10

First example doesn't work though: const greeting = pipe('hello') | upper | ex('!!!') await greeting.run() // → "HELLO!!!" If you look at the tests file, it needs to be written like this to make it work: let greeting; (greeting = pipe('hello')) | upper | ex('!!!'); await greeting.run(); Which is not anymore as ergonomic.

I was playing with it, and you can do this, which looks a little better. const greeting = pipe('hello'); greeting | upper | ex('!!!'); await greeting.run(); // → "HELLO!!!" Since it uses the "Symbol.toPrimitive" method, you can use any operator (not just "bitwise OR" (|)). const greeting = pipe('hello'); greeting / upper * ex('!!!'); await greeting.run(); // → "HELLO!!!"

Post by Timwi » Wed, Oct 08, 2025, 9:54 PM UTC

eyelidlessness wrote: post #69

IshKebab wrote: post #67

Earlier quoted context omitted.

`map` returns an array and can only be called on an array.

Right, but I’m not clear on what gets converted to an array. Do you mean more or less what I said in my previous comment? That it requires you (your code, or calling code in general) to perform that conversion excessively?

Post by bitwize » Wed, Oct 08, 2025, 10:31 PM UTC

Post by kazinator » Thu, Oct 09, 2025, 12:15 AM UTC

bobbylarrybobby wrote: post #54

rco8786 wrote: post #48

Earlier quoted context omitted.

Is there a language that can’t be contorted in surprising ways that I’m unaware of?

LISP — the contortions are expected, not surprises